A door-locking system for a motor vehicle with motor vehicle doors and a trunk lid can have a mechanical motor vehicle door lock in each of the motor vehicle doors and in the trunk lid, a mechanical lock cylinder in the door lock of the driver's door and a remotely controllable electronic operating device with a transmitter as an electronic key, a receiver and decoder and a power supply.
The door locks in the motor vehicle doors have at least one locked configuration and an additional theft preventative configuration.
The motor vehicle door locks have a central lock mechanism drive with control positions for engagement and/or disengagement of the theft preventative configuration and the central lock mechanism drive is operable by the electronic operating device.
In this door-lock system the motor vehicle door locks in the motor vehicle doors can be locked and unlocked mechanically from the inside so that the motor vehicle doors can be opened in any event from the inside.
The theft preventative mechanism can not be deactivated understandably from the inside, because if it could be so deactivated, the thief could break in a motor vehicle window pane of the theft protected vehicle and disengage the theft preventative configuration.
In the known motor vehicle door-lock system on which our invention is based the decoder and the receiver form a single unit which is mounted in the inside of the motor vehicle. Should the driver climb in the motor vehicle and accidentally operate the transmitter, i.e. the electronic key, the theft preventative mechanism would be engaged and could not be shut-off mechanically from the interior in case of danger. That impairs the security of the driver and possibly the passenger.
In particular from the state of the art and historically, the following should be noted: Door lock systems for motor vehicles with a central lock mechanism and if necessary special motor vehicle door lock mechanisms are known to have different forms.
Particularly, there are lock systems in which a special theft preventative configuration is possible as well as the standard locked and unlocked configuration (compare German Pat. Nos. 29 11 630, 29 11 680, 30 31 066 and 34 43 287).
The theft preventative configuration causes a positive locking inside the mechanism for central locking so that the standard lock knobs mounted inside in the driver's door and the interior operating mechanism are rendered inoperative. A driver's door equipped then for theft prevention cannot be secured from the inside. The driver's door cannot be opened from the exterior when the motor vehicle door lock is locked.
Should a theft preventative mechanism be engaged from the inside of the motor vehicle, one could, as already mentioned, be prevailed from leaving the motor vehicle in the usual direct way by simple mechanical operation.
To guarantee this type of escape in the past, one operated the standard mechanical lock cylinder, e.g. for door disengagement in the motor vehicle door, for disengagement and engagement of the theft preventative mechanism.
The mechanism can be designed so that in a locking displacement or motion in the lock cylinder the central lock mechanism goes into the theft preventative configuration.
In practice, however, differences can appear between the standard locked configuration and the theft preventative configuration in operation of this lock cylinder, especially in cases where large control displacements must be performed. Thus a special lock cylinder was developed (compare German Pat. Nos. 29 22 431, 29 36 402 and 31 20 222).
More recently, however, the mechanical lock cylinder for operation of a central lock mechanism and for engagement or disengagement of the theft preventative configuration was replaced by an electronic remotely operated door lock system (German Pat. Nos. 32 44 049 and 33 00 732). This door-lock system comprises, in everyday application, one or more transmitters, i.e. electronic keys, and a receiver with a decoder, which is placed in the motor vehicle interior. Then the problems described are present.